Playpen frame structure

Abstract

A playpen frame structure comprising a rectangular top rail frame supported by four upright legs. Each side of the top rail includes a joint in its center to allow the frame to collapse. A reinforcement structure is provided on the lower ends of the supporting legs comprising reinforcement bars extending diagonally from the lower ends of the legs and pivotally connected to a central member.

What is claimed is: 
     
       1. A playpen frame structure comprising: a rectangular top rail structure which is defined by four top rails pivotally connected by four corner joints; and   a leg structure which comprises four upright legs, each having an upper end and a lower end pivotally connected at the upper end thereof to the respective corner joint;   each of the top rails comprising two bar members which are pivotally connected to a common mid-joint, said mid-joint comprising as joint body having two side plates which are substantially parallel with each other and connected together at a portion thereof by a connecting piece to define a space for receiving a terminal portion of each of the two bar members, pivots being provided to secure the terminal portions of the bar members to the joint body to allow the bar members to rotate with respect to the joint body between an expanded position and a folded position, each of said bar members having an interior space in the terminal portion thereof to receive therein a leaf spring-like resilient retaining member which has two retaining pins each biased by the resilience thereof to project out through a hole formed on the bar member and to engage a hole formed on the joint body in order to retain the bar member with respect to the joint body;   a release member is provided to release the engagement between the bar members and the joint body to allow the joint body to be rotated from the expanded position to the folded position;   a reinforcement structure which comprises four reinforcement bars, each having a first end pivotally connected to the lower end of the respective upright leg and extending diagonally therefrom, and pivotally connected at a second end thereof to a central joint, said central joint comprising a central joint body on which four seats are formed for respectively receiving therein and pivotally securing thereon a connector by a pivot, each of the connectors in turn securely connecting the second end of the respective reinforcement bar to define the pivotal connection between the reinforcement bar and the central joint, said central joint body further comprising a central leg extending downward from an underside thereof to provide further support to said playpen frame; and   a bar support member which is in the form of a ring having a central opening to fit over the central leg of said central joint body and movably secured thereon by securing means; the bar support member is used to maintain the reinforcement structure in an extended position, said bar support member having a plurality of support arms extending therefrom a distance sufficient to contact and thus brace the respective connectors.   
     
     
       2. A playpen frame structure as claimed in claim 1, wherein said release member comprising a sheet member having thereon four flaps each having an inward projection corresponding to one of the retaining pins of the resilient retainer members so that when external forces are applied on the flaps, the inward projections push the retaining pins, against the biasing resilience thereof, into the bar members to break the engagement therebetween. 
     
     
       3. A playpen frame structure as claimed in claim 2, wherein said sheet member is secured on said joint body by a bolt extending through both the sheet and the joint body. 
     
     
       4. A playpen frame structure as claimed in claim 2, wherein said sheet member comprises a weakened portion associated with each of said flaps to serve as a rotatable connection therebetween. 
     
     
       5. A playpen frame structure as claimed in claim 1 wherein said securing means comprises at least a dowel pin extending downward from the underside of said central joint body and having an inner-threaded hole for engaging a screw and a corresponding elongated annular slot to receive therein the dowel pin so as to support said bar support member on said central joint body by tightening said screw in said inner-threaded hole. 
     
     
       6. A playpen frame structure as claimed in claim 1 wherein said bar support member is rotatable about said central leg between a first position which is the expanded position where said support arms contact and hold the reinforcement bars in the expanded condition and a second position where said support arms disengage from and thus releasing said reinforcement bars. 
     
     
       7. A playpen frame structure as claimed in claim 1 wherein said bar support member further comprises at least a seat for removably securing therein an auxiliary reinforcement bar extending outward therefrom. 
     
     
       8. A playpen frame structure as claimed in claim 5 wherein said elongated annular slot has two ends respectively defining a first and a second stop and wherein said bar support member is rotatable about said central leg between a first and a second position respectively determined by said stops, said first position being the expanded position where said support arms contact and hold the reinforcement bars in the expanded condition and said second position being a position where said support arms disengage from and thus releasing said reinforcement bars.